On Fri, Sep 25, 2020 at 3:49 PM Steve Sakoman <st...@sakoman.com> wrote:
>
> On Fri, Sep 25, 2020 at 6:52 AM Bruce Ashfield <bruce.ashfi...@gmail.com>
> wrote:
> >
> > On Fri, Sep 25, 2020 at 12:43 PM Steve Sakoman <st...@sakoman.com> wrote:
> > >
> > > Dunfell is still at 2.11.2. Will there be a need for patches to this
> > > version too? Or should I take the lttng version bump along with the
> > > 5.4 version bumps that cause the issue?
> >
> > I don't see a lot of options on that front. Unless we do some custom
> > backports.
> >
> > I just checked the lttng 2.11 branch, and the last commit is from January,
> > which
> > is too old to cover these -stable kernel bump issues.
> >
> > I can have a go at the backports, but we should be prepared to bend the
> > version
> > upgrade rule if that gets too complex (and for the record, I've never
> > had much luck
> > with lttng fixes).
>
> Totally understood! I think this is likely one of those cases where
> we'll have to take an exception to the upgrade rule.
>
> If you see issues with a backport just let me know and I'll go with
> the version upgrade approach.
I'll have a go at some backports on Monday and send info by end of day.
>
> While I have your attention, what about "linux-yocto/config:
> netfilter: Enable nat for ipv4 and ipv6" for dunfell? I'll have to
> prune out the changes for 5.8 in the commit, but does it make sense
> for 5.4?
It isn't a bugfix by a strict definition, but it also won't hurt
anything. It does
make sense to keep 5.4 & 5.8 kernel configuration consistent whenever
possible, so I'd say go ahead and do the port.
Bruce
>
> Thanks!
>
> Steve
>
>
> >
> > > On Mon, Sep 14, 2020 at 12:34 PM Bruce Ashfield
> > > <bruce.ashfi...@gmail.com> wrote:
> > > >
> > > > From: Jens Rehsack <s...@netbsd.org>
> > > >
> > > > Backporting the 10 patches since the lttng 2.12.2 release. We'll drop
> > > > them once .3 is released, but for now, we need the fixes to build
> > > > against the latest 5.4, 5.8 and 5.9 kernels.
> > > >
> > > > We also bump the devupstream SRCREV to pickup the same changes.
> > > >
> > > > Signed-off-by: Bruce Ashfield <bruce.ashfi...@gmail.com>
> > > > ---
> > > > ...ndency-issue-when-building-in-tree-w.patch | 54 ++
> > > > ...ce.h-into-the-mmu-sub-directory-v5.9.patch | 41 +
> > > > ...Make-kvm_mmu_page-definition-and-acc.patch | 39 +
> > > > ...he-length-of-per-inode-prealloc-list.patch | 84 ++
> > > > ...e-via-a-block-bitmap-read-is-prefetc.patch | 63 ++
> > > > ...al-of-smp_-read_barrier_depends-v5.9.patch | 391 ++++++++
> > > > ...teback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch | 59 ++
> > > > ...x-sync-livelock-due-to-b_dirty_time-.patch | 117 +++
> > > > ...es-for-ext4_discard_preallocations-a.patch | 52 +
> > > > .../0010-Fix-system-call-filter-table.patch | 918 ++++++++++++++++++
> > > > .../lttng/lttng-modules_2.12.2.bb | 12 +-
> > > > 11 files changed, 1829 insertions(+), 1 deletion(-)
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0001-Kconfig-fix-dependency-issue-when-building-in-tree-w.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0002-fix-Move-mmutrace.h-into-the-mmu-sub-directory-v5.9.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0003-fix-KVM-x86-mmu-Make-kvm_mmu_page-definition-and-acc.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0004-fix-ext4-limit-the-length-of-per-inode-prealloc-list.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0005-fix-ext4-indicate-via-a-block-bitmap-read-is-prefetc.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0007-fix-writeback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0008-fix-writeback-Fix-sync-livelock-due-to-b_dirty_time-.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0009-fix-version-ranges-for-ext4_discard_preallocations-a.patch
> > > > create mode 100644
> > > > meta/recipes-kernel/lttng/lttng-modules/0010-Fix-system-call-filter-table.patch
> > > >
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0001-Kconfig-fix-dependency-issue-when-building-in-tree-w.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0001-Kconfig-fix-dependency-issue-when-building-in-tree-w.patch
> > > > new file mode 100644
> > > > index 0000000000..ae8bec45de
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0001-Kconfig-fix-dependency-issue-when-building-in-tree-w.patch
> > > > @@ -0,0 +1,54 @@
> > > > +From ff4d1d7e85be94ef43709cd698f0ec9a12f247d1 Mon Sep 17 00:00:00 2001
> > > > +From: Beniamin Sandu <beniaminsa...@gmail.com>
> > > > +Date: Thu, 13 Aug 2020 16:24:39 +0300
> > > > +Subject: [PATCH 01/10] Kconfig: fix dependency issue when building
> > > > in-tree
> > > > + without CONFIG_FTRACE
> > > > +
> > > > +When building in-tree, one could disable CONFIG_FTRACE from kernel
> > > > +config which will leave CONFIG_TRACEPOINTS selected by LTTNG modules,
> > > > +but generate a lot of linker errors like below because it leaves out
> > > > +other stuff, e.g.:
> > > > +
> > > > +trace.c:(.text+0xd86b): undefined reference to
> > > > `trace_event_buffer_reserve'
> > > > +ld: trace.c:(.text+0xd8de): undefined reference to
> > > > `trace_event_buffer_commit'
> > > > +ld: trace.c:(.text+0xd926): undefined reference to
> > > > `event_triggers_call'
> > > > +ld: trace.c:(.text+0xd942): undefined reference to
> > > > `trace_event_ignore_this_pid'
> > > > +ld: net/mac80211/trace.o: in function
> > > > `trace_event_raw_event_drv_tdls_cancel_channel_switch':
> > > > +
> > > > +It appears to be caused by the fact that TRACE_EVENT macros in the
> > > > Linux
> > > > +kernel depend on the Ftrace ring buffer as soon as CONFIG_TRACEPOINTS
> > > > is
> > > > +enabled.
> > > > +
> > > > +Steps to reproduce:
> > > > +
> > > > +- Get a clone of an upstream stable kernel and use scripts/built-in.sh
> > > > on it
> > > > +
> > > > +- Configure a standard x86-64 build, enable built-in LTTNG but disable
> > > > + CONFIG_FTRACE from Kernel Hacking-->Tracers using menuconfig
> > > > +
> > > > +- Build will fail at linking stage
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Beniamin Sandu <beniaminsa...@gmail.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + Kconfig | 2 +-
> > > > + 1 file changed, 1 insertion(+), 1 deletion(-)
> > > > +
> > > > +diff --git a/Kconfig b/Kconfig
> > > > +index acdab73..10eccff 100644
> > > > +--- a/Kconfig
> > > > ++++ b/Kconfig
> > > > +@@ -2,7 +2,7 @@
> > > > +
> > > > + config LTTNG
> > > > + tristate "LTTng support"
> > > > +- select TRACEPOINTS
> > > > ++ select TRACING
> > > > + help
> > > > + LTTng is an open source tracing framework for Linux.
> > > > +
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0002-fix-Move-mmutrace.h-into-the-mmu-sub-directory-v5.9.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0002-fix-Move-mmutrace.h-into-the-mmu-sub-directory-v5.9.patch
> > > > new file mode 100644
> > > > index 0000000000..fab673b854
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0002-fix-Move-mmutrace.h-into-the-mmu-sub-directory-v5.9.patch
> > > > @@ -0,0 +1,41 @@
> > > > +From e10ab43dd0e425df5bc0ac763447664ed075ba05 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 10 Aug 2020 11:22:05 -0400
> > > > +Subject: [PATCH 02/10] fix: Move mmutrace.h into the mmu/
> > > > sub-directory (v5.9)
> > > > +
> > > > + commit 33e3042dac6bcc33b80835f7d7b502b1d74c457c
> > > > + Author: Sean Christopherson <sean.j.christopher...@intel.com>
> > > > + Date: Mon Jun 22 13:20:29 2020 -0700
> > > > +
> > > > + KVM: x86/mmu: Move mmu_audit.c and mmutrace.h into the mmu/
> > > > sub-directory
> > > > +
> > > > + Move mmu_audit.c and mmutrace.h under mmu/ where they belong.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Change-Id: I582525ccca34e1e3bd62870364108a7d3e9df2e4
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + probes/lttng-probe-kvm-x86-mmu.c | 4 ++++
> > > > + 1 file changed, 4 insertions(+)
> > > > +
> > > > +diff --git a/probes/lttng-probe-kvm-x86-mmu.c
> > > > b/probes/lttng-probe-kvm-x86-mmu.c
> > > > +index 37384a2..5a7ef1e 100644
> > > > +--- a/probes/lttng-probe-kvm-x86-mmu.c
> > > > ++++ b/probes/lttng-probe-kvm-x86-mmu.c
> > > > +@@ -24,7 +24,11 @@
> > > > + */
> > > > + #include <wrapper/tracepoint.h>
> > > > +
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++#include <../../arch/x86/kvm/mmu/mmutrace.h>
> > > > ++#else
> > > > + #include <../../arch/x86/kvm/mmutrace.h>
> > > > ++#endif
> > > > +
> > > > + #undef TRACE_INCLUDE_PATH
> > > > + #undef TRACE_INCLUDE_FILE
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0003-fix-KVM-x86-mmu-Make-kvm_mmu_page-definition-and-acc.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0003-fix-KVM-x86-mmu-Make-kvm_mmu_page-definition-and-acc.patch
> > > > new file mode 100644
> > > > index 0000000000..524631cc72
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0003-fix-KVM-x86-mmu-Make-kvm_mmu_page-definition-and-acc.patch
> > > > @@ -0,0 +1,39 @@
> > > > +From f16315cc45c4c6b880de541bb092ca18a13952b7 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 10 Aug 2020 11:36:03 -0400
> > > > +Subject: [PATCH 03/10] fix: KVM: x86/mmu: Make kvm_mmu_page definition
> > > > and
> > > > + accessor internal-only (v5.9)
> > > > +
> > > > + commit 985ab2780164698ec6e7d73fad523d50449261dd
> > > > + Author: Sean Christopherson <sean.j.christopher...@intel.com>
> > > > + Date: Mon Jun 22 13:20:32 2020 -0700
> > > > +
> > > > + KVM: x86/mmu: Make kvm_mmu_page definition and accessor
> > > > internal-only
> > > > +
> > > > + Make 'struct kvm_mmu_page' MMU-only, nothing outside of the MMU
> > > > should
> > > > + be poking into the gory details of shadow pages.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Change-Id: Ia5c1b9c49c2b00dad1d5b17c50c3dc730dafda20
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + probes/lttng-probe-kvm-x86-mmu.c | 1 +
> > > > + 1 file changed, 1 insertion(+)
> > > > +
> > > > +diff --git a/probes/lttng-probe-kvm-x86-mmu.c
> > > > b/probes/lttng-probe-kvm-x86-mmu.c
> > > > +index 5a7ef1e..8f98186 100644
> > > > +--- a/probes/lttng-probe-kvm-x86-mmu.c
> > > > ++++ b/probes/lttng-probe-kvm-x86-mmu.c
> > > > +@@ -25,6 +25,7 @@
> > > > + #include <wrapper/tracepoint.h>
> > > > +
> > > > + #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++#include <../../arch/x86/kvm/mmu/mmu_internal.h>
> > > > + #include <../../arch/x86/kvm/mmu/mmutrace.h>
> > > > + #else
> > > > + #include <../../arch/x86/kvm/mmutrace.h>
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0004-fix-ext4-limit-the-length-of-per-inode-prealloc-list.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0004-fix-ext4-limit-the-length-of-per-inode-prealloc-list.patch
> > > > new file mode 100644
> > > > index 0000000000..e29c07252c
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0004-fix-ext4-limit-the-length-of-per-inode-prealloc-list.patch
> > > > @@ -0,0 +1,84 @@
> > > > +From 8fe742807e65af29dac3fea568ff93cbc5dd9a56 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 24 Aug 2020 15:26:04 -0400
> > > > +Subject: [PATCH 04/10] fix: ext4: limit the length of per-inode
> > > > prealloc list
> > > > + (v5.9)
> > > > +MIME-Version: 1.0
> > > > +Content-Type: text/plain; charset=UTF-8
> > > > +Content-Transfer-Encoding: 8bit
> > > > +
> > > > +See upstream commit:
> > > > +
> > > > + commit 27bc446e2def38db3244a6eb4bb1d6312936610a
> > > > + Author: brookxu <brookxu...@gmail.com>
> > > > + Date: Mon Aug 17 15:36:15 2020 +0800
> > > > +
> > > > + ext4: limit the length of per-inode prealloc list
> > > > +
> > > > + In the scenario of writing sparse files, the per-inode prealloc
> > > > list may
> > > > + be very long, resulting in high overhead for
> > > > ext4_mb_use_preallocated().
> > > > + To circumvent this problem, we limit the maximum length of
> > > > per-inode
> > > > + prealloc list to 512 and allow users to modify it.
> > > > +
> > > > + After patching, we observed that the sys ratio of cpu has dropped,
> > > > and
> > > > + the system throughput has increased significantly. We created a
> > > > process
> > > > + to write the sparse file, and the running time of the process on
> > > > the
> > > > + fixed kernel was significantly reduced, as follows:
> > > > +
> > > > + Running time on unfixed kernel：
> > > > + [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
> > > > + real 0m2.051s
> > > > + user 0m0.008s
> > > > + sys 0m2.026s
> > > > +
> > > > + Running time on fixed kernel：
> > > > + [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
> > > > + real 0m0.471s
> > > > + user 0m0.004s
> > > > + sys 0m0.395s
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +Change-Id: I5169cb24853d4da32e2862a6626f1f058689b053
> > > > +---
> > > > + instrumentation/events/lttng-module/ext4.h | 15 +++++++++++++++
> > > > + 1 file changed, 15 insertions(+)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/ext4.h
> > > > b/instrumentation/events/lttng-module/ext4.h
> > > > +index 5f7ab28..72ad4c9 100644
> > > > +--- a/instrumentation/events/lttng-module/ext4.h
> > > > ++++ b/instrumentation/events/lttng-module/ext4.h
> > > > +@@ -460,6 +460,20 @@ LTTNG_TRACEPOINT_EVENT(ext4_mb_release_group_pa,
> > > > + )
> > > > + #endif
> > > > +
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
> > > > ++ TP_PROTO(struct inode *inode, unsigned int len, unsigned int
> > > > needed),
> > > > ++
> > > > ++ TP_ARGS(inode, len, needed),
> > > > ++
> > > > ++ TP_FIELDS(
> > > > ++ ctf_integer(dev_t, dev, inode->i_sb->s_dev)
> > > > ++ ctf_integer(ino_t, ino, inode->i_ino)
> > > > ++ ctf_integer(unsigned int, len, len)
> > > > ++ ctf_integer(unsigned int, needed, needed)
> > > > ++ )
> > > > ++)
> > > > ++#else
> > > > + LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
> > > > + TP_PROTO(struct inode *inode),
> > > > +
> > > > +@@ -470,6 +484,7 @@ LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
> > > > + ctf_integer(ino_t, ino, inode->i_ino)
> > > > + )
> > > > + )
> > > > ++#endif
> > > > +
> > > > + LTTNG_TRACEPOINT_EVENT(ext4_mb_discard_preallocations,
> > > > + TP_PROTO(struct super_block *sb, int needed),
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0005-fix-ext4-indicate-via-a-block-bitmap-read-is-prefetc.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0005-fix-ext4-indicate-via-a-block-bitmap-read-is-prefetc.patch
> > > > new file mode 100644
> > > > index 0000000000..f76e9698c8
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0005-fix-ext4-indicate-via-a-block-bitmap-read-is-prefetc.patch
> > > > @@ -0,0 +1,63 @@
> > > > +From 52563d02a9234215b62c5f519aa1b5d8589ccd0a Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 24 Aug 2020 15:37:50 -0400
> > > > +Subject: [PATCH 05/10]
> > > > =?UTF-8?q?fix:=20ext4:=20indicate=20via=20a=20block?=
> > > > + =?UTF-8?q?=20bitmap=20read=20is=20prefetched=E2=80=A6=20(v5.9)?=
> > > > +MIME-Version: 1.0
> > > > +Content-Type: text/plain; charset=UTF-8
> > > > +Content-Transfer-Encoding: 8bit
> > > > +
> > > > +See upstream commit:
> > > > +
> > > > + commit ab74c7b23f3770935016e3eb3ecdf1e42b73efaa
> > > > + Author: Theodore Ts'o <ty...@mit.edu>
> > > > + Date: Wed Jul 15 11:48:55 2020 -0400
> > > > +
> > > > + ext4: indicate via a block bitmap read is prefetched via a
> > > > tracepoint
> > > > +
> > > > + Modify the ext4_read_block_bitmap_load tracepoint so that it tells
> > > > us
> > > > + whether a block bitmap is being prefetched.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +Change-Id: I0e5e2c5b8004223d0928235c092449ee16a940e1
> > > > +---
> > > > + instrumentation/events/lttng-module/ext4.h | 14 ++++++++++++++
> > > > + 1 file changed, 14 insertions(+)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/ext4.h
> > > > b/instrumentation/events/lttng-module/ext4.h
> > > > +index 72ad4c9..4476abb 100644
> > > > +--- a/instrumentation/events/lttng-module/ext4.h
> > > > ++++ b/instrumentation/events/lttng-module/ext4.h
> > > > +@@ -893,12 +893,26 @@
> > > > LTTNG_TRACEPOINT_EVENT_INSTANCE(ext4__bitmap_load,
> > > > ext4_mb_buddy_bitmap_load,
> > > > + TP_ARGS(sb, group)
> > > > + )
> > > > +
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++LTTNG_TRACEPOINT_EVENT(ext4_read_block_bitmap_load,
> > > > ++ TP_PROTO(struct super_block *sb, unsigned long group, bool
> > > > prefetch),
> > > > ++
> > > > ++ TP_ARGS(sb, group, prefetch),
> > > > ++
> > > > ++ TP_FIELDS(
> > > > ++ ctf_integer(dev_t, dev, sb->s_dev)
> > > > ++ ctf_integer(__u32, group, group)
> > > > ++ ctf_integer(bool, prefetch, prefetch)
> > > > ++ )
> > > > ++)
> > > > ++#else
> > > > + LTTNG_TRACEPOINT_EVENT_INSTANCE(ext4__bitmap_load,
> > > > ext4_read_block_bitmap_load,
> > > > +
> > > > + TP_PROTO(struct super_block *sb, unsigned long group),
> > > > +
> > > > + TP_ARGS(sb, group)
> > > > + )
> > > > ++#endif
> > > > +
> > > > + LTTNG_TRACEPOINT_EVENT_INSTANCE(ext4__bitmap_load,
> > > > ext4_load_inode_bitmap,
> > > > +
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
> > > > new file mode 100644
> > > > index 0000000000..0970dd30aa
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
> > > > @@ -0,0 +1,391 @@
> > > > +From 57ccbfa6a8a79c7b84394c2097efaf7935607aa5 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Tue, 25 Aug 2020 10:56:29 -0400
> > > > +Subject: [PATCH 06/10] fix: removal of [smp_]read_barrier_depends
> > > > (v5.9)
> > > > +
> > > > +See upstream commits:
> > > > +
> > > > + commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
> > > > + Author: Will Deacon <w...@kernel.org>
> > > > + Date: Tue Oct 24 11:22:47 2017 +0100
> > > > +
> > > > + locking/barriers: Add implicit smp_read_barrier_depends() to
> > > > READ_ONCE()
> > > > +
> > > > + In preparation for the removal of lockless_dereference(), which is
> > > > the
> > > > + same as READ_ONCE() on all architectures other than Alpha, add an
> > > > + implicit smp_read_barrier_depends() to READ_ONCE() so that it can
> > > > be
> > > > + used to head dependency chains on all architectures.
> > > > +
> > > > + commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
> > > > + Author: Will Deacon <will.dea...@arm.com>
> > > > + Date: Tue Oct 24 11:22:47 2017 +0100
> > > > +
> > > > + locking/barriers: Add implicit smp_read_barrier_depends() to
> > > > READ_ONCE()
> > > > +
> > > > + In preparation for the removal of lockless_dereference(), which is
> > > > the
> > > > + same as READ_ONCE() on all architectures other than Alpha, add an
> > > > + implicit smp_read_barrier_depends() to READ_ONCE() so that it can
> > > > be
> > > > + used to head dependency chains on all architectures.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Change-Id: Ife8880bd9378dca2972da8838f40fc35ccdfaaac
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + instrumentation/events/lttng-module/i2c.h | 4 ++--
> > > > + lib/ringbuffer/backend.h | 2 +-
> > > > + lib/ringbuffer/backend_internal.h | 2 +-
> > > > + lib/ringbuffer/frontend.h | 4 ++--
> > > > + lib/ringbuffer/ring_buffer_frontend.c | 4 ++--
> > > > + lib/ringbuffer/ring_buffer_iterator.c | 2 +-
> > > > + lttng-events.c | 8 ++++----
> > > > + probes/lttng-kprobes.c | 6 +++---
> > > > + probes/lttng-kretprobes.c | 6 +++---
> > > > + probes/lttng-tracepoint-event-impl.h | 12 ++++++------
> > > > + probes/lttng-uprobes.c | 6 +++---
> > > > + wrapper/compiler.h | 18 ++++++++++++++++++
> > > > + wrapper/trace-clock.h | 15 +++++----------
> > > > + 13 files changed, 51 insertions(+), 38 deletions(-)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/i2c.h
> > > > b/instrumentation/events/lttng-module/i2c.h
> > > > +index dcbabf6..131d134 100644
> > > > +--- a/instrumentation/events/lttng-module/i2c.h
> > > > ++++ b/instrumentation/events/lttng-module/i2c.h
> > > > +@@ -23,7 +23,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_write,
> > > > +
> > > > + TP_code_pre(
> > > > + tp_locvar->extract_sensitive_payload =
> > > > +- READ_ONCE(extract_sensitive_payload);
> > > > ++ LTTNG_READ_ONCE(extract_sensitive_payload);
> > > > + ),
> > > > +
> > > > + TP_FIELDS(
> > > > +@@ -78,7 +78,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_reply,
> > > > +
> > > > + TP_code_pre(
> > > > + tp_locvar->extract_sensitive_payload =
> > > > +- READ_ONCE(extract_sensitive_payload);
> > > > ++ LTTNG_READ_ONCE(extract_sensitive_payload);
> > > > + ),
> > > > +
> > > > + TP_FIELDS(
> > > > +diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h
> > > > +index da937f2..43e1d47 100644
> > > > +--- a/lib/ringbuffer/backend.h
> > > > ++++ b/lib/ringbuffer/backend.h
> > > > +@@ -156,7 +156,7 @@ size_t lib_ring_buffer_do_strcpy(const struct
> > > > lib_ring_buffer_config *config,
> > > > + * Only read source character once, in case it is
> > > > + * modified concurrently.
> > > > + */
> > > > +- c = READ_ONCE(src[count]);
> > > > ++ c = LTTNG_READ_ONCE(src[count]);
> > > > + if (!c)
> > > > + break;
> > > > + lib_ring_buffer_do_copy(config, &dest[count], &c, 1);
> > > > +diff --git a/lib/ringbuffer/backend_internal.h
> > > > b/lib/ringbuffer/backend_internal.h
> > > > +index 2d6a345..1226fd8 100644
> > > > +--- a/lib/ringbuffer/backend_internal.h
> > > > ++++ b/lib/ringbuffer/backend_internal.h
> > > > +@@ -367,7 +367,7 @@ void lib_ring_buffer_clear_noref(const struct
> > > > lib_ring_buffer_config *config,
> > > > + * Performing a volatile access to read the sb_pages, because
> > > > we want to
> > > > + * read a coherent version of the pointer and the associated
> > > > noref flag.
> > > > + */
> > > > +- id = READ_ONCE(bufb->buf_wsb[idx].id);
> > > > ++ id = LTTNG_READ_ONCE(bufb->buf_wsb[idx].id);
> > > > + for (;;) {
> > > > + /* This check is called on the fast path for each
> > > > record. */
> > > > + if (likely(!subbuffer_id_is_noref(config, id))) {
> > > > +diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h
> > > > +index 6f516d9..41382fe 100644
> > > > +--- a/lib/ringbuffer/frontend.h
> > > > ++++ b/lib/ringbuffer/frontend.h
> > > > +@@ -79,7 +79,7 @@ void *channel_destroy(struct channel *chan);
> > > > + #define for_each_channel_cpu(cpu, chan)
> > > > \
> > > > + for ((cpu) = -1;
> > > > \
> > > > + ({ (cpu) = cpumask_next(cpu, (chan)->backend.cpumask);
> > > > \
> > > > +- smp_read_barrier_depends(); (cpu) < nr_cpu_ids; });)
> > > > ++ smp_rmb(); (cpu) < nr_cpu_ids; });)
> > > > +
> > > > + extern struct lib_ring_buffer *channel_get_ring_buffer(
> > > > + const struct lib_ring_buffer_config
> > > > *config,
> > > > +@@ -155,7 +155,7 @@ static inline
> > > > + int lib_ring_buffer_is_finalized(const struct lib_ring_buffer_config
> > > > *config,
> > > > + struct lib_ring_buffer *buf)
> > > > + {
> > > > +- int finalized = READ_ONCE(buf->finalized);
> > > > ++ int finalized = LTTNG_READ_ONCE(buf->finalized);
> > > > + /*
> > > > + * Read finalized before counters.
> > > > + */
> > > > +diff --git a/lib/ringbuffer/ring_buffer_frontend.c
> > > > b/lib/ringbuffer/ring_buffer_frontend.c
> > > > +index 3cab365..4980d20 100644
> > > > +--- a/lib/ringbuffer/ring_buffer_frontend.c
> > > > ++++ b/lib/ringbuffer/ring_buffer_frontend.c
> > > > +@@ -1074,7 +1074,7 @@ int lib_ring_buffer_snapshot(struct
> > > > lib_ring_buffer *buf,
> > > > + int finalized;
> > > > +
> > > > + retry:
> > > > +- finalized = READ_ONCE(buf->finalized);
> > > > ++ finalized = LTTNG_READ_ONCE(buf->finalized);
> > > > + /*
> > > > + * Read finalized before counters.
> > > > + */
> > > > +@@ -1245,7 +1245,7 @@ int lib_ring_buffer_get_subbuf(struct
> > > > lib_ring_buffer *buf,
> > > > + return -EBUSY;
> > > > + }
> > > > + retry:
> > > > +- finalized = READ_ONCE(buf->finalized);
> > > > ++ finalized = LTTNG_READ_ONCE(buf->finalized);
> > > > + /*
> > > > + * Read finalized before counters.
> > > > + */
> > > > +diff --git a/lib/ringbuffer/ring_buffer_iterator.c
> > > > b/lib/ringbuffer/ring_buffer_iterator.c
> > > > +index d25db72..7b4f20a 100644
> > > > +--- a/lib/ringbuffer/ring_buffer_iterator.c
> > > > ++++ b/lib/ringbuffer/ring_buffer_iterator.c
> > > > +@@ -46,7 +46,7 @@ restart:
> > > > + switch (iter->state) {
> > > > + case ITER_GET_SUBBUF:
> > > > + ret = lib_ring_buffer_get_next_subbuf(buf);
> > > > +- if (ret && !READ_ONCE(buf->finalized)
> > > > ++ if (ret && !LTTNG_READ_ONCE(buf->finalized)
> > > > + && config->alloc == RING_BUFFER_ALLOC_GLOBAL) {
> > > > + /*
> > > > + * Use "pull" scheme for global buffers. The
> > > > reader
> > > > +diff --git a/lttng-events.c b/lttng-events.c
> > > > +index be7e389..d719294 100644
> > > > +--- a/lttng-events.c
> > > > ++++ b/lttng-events.c
> > > > +@@ -1719,7 +1719,7 @@ int lttng_metadata_printf(struct lttng_session
> > > > *session,
> > > > + size_t len;
> > > > + va_list ap;
> > > > +
> > > > +- WARN_ON_ONCE(!READ_ONCE(session->active));
> > > > ++ WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
> > > > +
> > > > + va_start(ap, fmt);
> > > > + str = kvasprintf(GFP_KERNEL, fmt, ap);
> > > > +@@ -2305,7 +2305,7 @@ int _lttng_event_metadata_statedump(struct
> > > > lttng_session *session,
> > > > + {
> > > > + int ret = 0;
> > > > +
> > > > +- if (event->metadata_dumped || !READ_ONCE(session->active))
> > > > ++ if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
> > > > + return 0;
> > > > + if (chan->channel_type == METADATA_CHANNEL)
> > > > + return 0;
> > > > +@@ -2377,7 +2377,7 @@ int _lttng_channel_metadata_statedump(struct
> > > > lttng_session *session,
> > > > + {
> > > > + int ret = 0;
> > > > +
> > > > +- if (chan->metadata_dumped || !READ_ONCE(session->active))
> > > > ++ if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
> > > > + return 0;
> > > > +
> > > > + if (chan->channel_type == METADATA_CHANNEL)
> > > > +@@ -2604,7 +2604,7 @@ int _lttng_session_metadata_statedump(struct
> > > > lttng_session *session)
> > > > + struct lttng_event *event;
> > > > + int ret = 0;
> > > > +
> > > > +- if (!READ_ONCE(session->active))
> > > > ++ if (!LTTNG_READ_ONCE(session->active))
> > > > + return 0;
> > > > +
> > > > + lttng_metadata_begin(session);
> > > > +diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c
> > > > +index a44eaa1..38fb72e 100644
> > > > +--- a/probes/lttng-kprobes.c
> > > > ++++ b/probes/lttng-kprobes.c
> > > > +@@ -31,11 +31,11 @@ int lttng_kprobes_handler_pre(struct kprobe *p,
> > > > struct pt_regs *regs)
> > > > + int ret;
> > > > + unsigned long data = (unsigned long) p->addr;
> > > > +
> > > > +- if (unlikely(!READ_ONCE(chan->session->active)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(chan->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(event->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
> > > > + return 0;
> > > > +
> > > > + lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx,
> > > > sizeof(data),
> > > > +diff --git a/probes/lttng-kretprobes.c b/probes/lttng-kretprobes.c
> > > > +index ab98ff2..a6bcd21 100644
> > > > +--- a/probes/lttng-kretprobes.c
> > > > ++++ b/probes/lttng-kretprobes.c
> > > > +@@ -51,11 +51,11 @@ int _lttng_kretprobes_handler(struct
> > > > kretprobe_instance *krpi,
> > > > + unsigned long parent_ip;
> > > > + } payload;
> > > > +
> > > > +- if (unlikely(!READ_ONCE(chan->session->active)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(chan->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(event->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
> > > > + return 0;
> > > > +
> > > > + payload.ip = (unsigned long) krpi->rp->kp.addr;
> > > > +diff --git a/probes/lttng-tracepoint-event-impl.h
> > > > b/probes/lttng-tracepoint-event-impl.h
> > > > +index 77b8638..72a669e 100644
> > > > +--- a/probes/lttng-tracepoint-event-impl.h
> > > > ++++ b/probes/lttng-tracepoint-event-impl.h
> > > > +@@ -1132,11 +1132,11 @@ static void __event_probe__##_name(void
> > > > *__data, _proto) \
> > > > +
> > > > \
> > > > + if (!_TP_SESSION_CHECK(session, __session))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__session->active)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__session->active)))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__chan->enabled)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled)))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__event->enabled)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__event->enabled)))
> > > > \
> > > > + return;
> > > > \
> > > > + __lf = lttng_rcu_dereference(__session->pid_tracker.p);
> > > > \
> > > > + if (__lf && likely(!lttng_id_tracker_lookup(__lf,
> > > > current->tgid))) \
> > > > +@@ -1225,11 +1225,11 @@ static void __event_probe__##_name(void
> > > > *__data) \
> > > > +
> > > > \
> > > > + if (!_TP_SESSION_CHECK(session, __session))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__session->active)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__session->active)))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__chan->enabled)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled)))
> > > > \
> > > > + return;
> > > > \
> > > > +- if (unlikely(!READ_ONCE(__event->enabled)))
> > > > \
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(__event->enabled)))
> > > > \
> > > > + return;
> > > > \
> > > > + __lf = lttng_rcu_dereference(__session->pid_tracker.p);
> > > > \
> > > > + if (__lf && likely(!lttng_id_tracker_lookup(__lf,
> > > > current->tgid))) \
> > > > +diff --git a/probes/lttng-uprobes.c b/probes/lttng-uprobes.c
> > > > +index bc10128..bda1d9b 100644
> > > > +--- a/probes/lttng-uprobes.c
> > > > ++++ b/probes/lttng-uprobes.c
> > > > +@@ -40,11 +40,11 @@ int lttng_uprobes_handler_pre(struct
> > > > uprobe_consumer *uc, struct pt_regs *regs)
> > > > + unsigned long ip;
> > > > + } payload;
> > > > +
> > > > +- if (unlikely(!READ_ONCE(chan->session->active)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(chan->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
> > > > + return 0;
> > > > +- if (unlikely(!READ_ONCE(event->enabled)))
> > > > ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
> > > > + return 0;
> > > > +
> > > > + lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx,
> > > > +diff --git a/wrapper/compiler.h b/wrapper/compiler.h
> > > > +index 1496f33..b9f8c51 100644
> > > > +--- a/wrapper/compiler.h
> > > > ++++ b/wrapper/compiler.h
> > > > +@@ -9,6 +9,7 @@
> > > > + #define _LTTNG_WRAPPER_COMPILER_H
> > > > +
> > > > + #include <linux/compiler.h>
> > > > ++#include <linux/version.h>
> > > > +
> > > > + /*
> > > > + * Don't allow compiling with buggy compiler.
> > > > +@@ -39,4 +40,21 @@
> > > > + # define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; })
> > > > + #endif
> > > > +
> > > > ++/*
> > > > ++ * In v4.15 a smp read barrier was added to READ_ONCE to replace
> > > > ++ * lockless_dereference(), replicate this behavior on prior kernels
> > > > ++ * and remove calls to smp_read_barrier_depends which was dropped
> > > > ++ * in v5.9.
> > > > ++ */
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0))
> > > > ++#define LTTNG_READ_ONCE(x) READ_ONCE(x)
> > > > ++#else
> > > > ++#define LTTNG_READ_ONCE(x) \
> > > > ++({ \
> > > > ++ typeof(x) __val = READ_ONCE(x); \
> > > > ++ smp_read_barrier_depends(); \
> > > > ++ __val; \
> > > > ++})
> > > > ++#endif
> > > > ++
> > > > + #endif /* _LTTNG_WRAPPER_COMPILER_H */
> > > > +diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
> > > > +index 9f4e366..187fc82 100644
> > > > +--- a/wrapper/trace-clock.h
> > > > ++++ b/wrapper/trace-clock.h
> > > > +@@ -160,33 +160,30 @@ static inline void put_trace_clock(void)
> > > > +
> > > > + static inline u64 trace_clock_read64(void)
> > > > + {
> > > > +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
> > > > ++ struct lttng_trace_clock *ltc =
> > > > LTTNG_READ_ONCE(lttng_trace_clock);
> > > > +
> > > > + if (likely(!ltc)) {
> > > > + return trace_clock_read64_monotonic();
> > > > + } else {
> > > > +- read_barrier_depends(); /* load ltc before content */
> > > > + return ltc->read64();
> > > > + }
> > > > + }
> > > > +
> > > > + static inline u64 trace_clock_freq(void)
> > > > + {
> > > > +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
> > > > ++ struct lttng_trace_clock *ltc =
> > > > LTTNG_READ_ONCE(lttng_trace_clock);
> > > > +
> > > > + if (!ltc) {
> > > > + return trace_clock_freq_monotonic();
> > > > + } else {
> > > > +- read_barrier_depends(); /* load ltc before content */
> > > > + return ltc->freq();
> > > > + }
> > > > + }
> > > > +
> > > > + static inline int trace_clock_uuid(char *uuid)
> > > > + {
> > > > +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
> > > > ++ struct lttng_trace_clock *ltc =
> > > > LTTNG_READ_ONCE(lttng_trace_clock);
> > > > +
> > > > +- read_barrier_depends(); /* load ltc before content */
> > > > + /* Use default UUID cb when NULL */
> > > > + if (!ltc || !ltc->uuid) {
> > > > + return trace_clock_uuid_monotonic(uuid);
> > > > +@@ -197,24 +194,22 @@ static inline int trace_clock_uuid(char *uuid)
> > > > +
> > > > + static inline const char *trace_clock_name(void)
> > > > + {
> > > > +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
> > > > ++ struct lttng_trace_clock *ltc =
> > > > LTTNG_READ_ONCE(lttng_trace_clock);
> > > > +
> > > > + if (!ltc) {
> > > > + return trace_clock_name_monotonic();
> > > > + } else {
> > > > +- read_barrier_depends(); /* load ltc before content */
> > > > + return ltc->name();
> > > > + }
> > > > + }
> > > > +
> > > > + static inline const char *trace_clock_description(void)
> > > > + {
> > > > +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
> > > > ++ struct lttng_trace_clock *ltc =
> > > > LTTNG_READ_ONCE(lttng_trace_clock);
> > > > +
> > > > + if (!ltc) {
> > > > + return trace_clock_description_monotonic();
> > > > + } else {
> > > > +- read_barrier_depends(); /* load ltc before content */
> > > > + return ltc->description();
> > > > + }
> > > > + }
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0007-fix-writeback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0007-fix-writeback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch
> > > > new file mode 100644
> > > > index 0000000000..2843c9cb62
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0007-fix-writeback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch
> > > > @@ -0,0 +1,59 @@
> > > > +From eae02feb58064eee5ce15a9f6bdffd107c47da05 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 31 Aug 2020 11:41:38 -0400
> > > > +Subject: [PATCH 07/10] fix: writeback: Drop I_DIRTY_TIME_EXPIRE (v5.9)
> > > > +
> > > > +See upstream commit:
> > > > +
> > > > + commit 5fcd57505c002efc5823a7355e21f48dd02d5a51
> > > > + Author: Jan Kara <j...@suse.cz>
> > > > + Date: Fri May 29 16:24:43 2020 +0200
> > > > +
> > > > + writeback: Drop I_DIRTY_TIME_EXPIRE
> > > > +
> > > > + The only use of I_DIRTY_TIME_EXPIRE is to detect in
> > > > + __writeback_single_inode() that inode got there because flush
> > > > worker
> > > > + decided it's time to writeback the dirty inode time stamps (either
> > > > + because we are syncing or because of age). However we can detect
> > > > this
> > > > + directly in __writeback_single_inode() and there's no need for the
> > > > + strange propagation with I_DIRTY_TIME_EXPIRE flag.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +Change-Id: I92e37c2ff3ec36d431e8f9de5c8e37c5a2da55ea
> > > > +---
> > > > + instrumentation/events/lttng-module/writeback.h | 16 +++++++++++++++-
> > > > + 1 file changed, 15 insertions(+), 1 deletion(-)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/writeback.h
> > > > b/instrumentation/events/lttng-module/writeback.h
> > > > +index affb4eb..ece67ad 100644
> > > > +--- a/instrumentation/events/lttng-module/writeback.h
> > > > ++++ b/instrumentation/events/lttng-module/writeback.h
> > > > +@@ -46,7 +46,21 @@ static inline struct backing_dev_info
> > > > *lttng_inode_to_bdi(struct inode *inode)
> > > > +
> > > > + #endif
> > > > +
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0))
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++#define show_inode_state(state)
> > > > \
> > > > ++ __print_flags(state, "|", \
> > > > ++ {I_DIRTY_SYNC, "I_DIRTY_SYNC"}, \
> > > > ++ {I_DIRTY_DATASYNC, "I_DIRTY_DATASYNC"}, \
> > > > ++ {I_DIRTY_PAGES, "I_DIRTY_PAGES"}, \
> > > > ++ {I_NEW, "I_NEW"}, \
> > > > ++ {I_WILL_FREE, "I_WILL_FREE"}, \
> > > > ++ {I_FREEING, "I_FREEING"}, \
> > > > ++ {I_CLEAR, "I_CLEAR"}, \
> > > > ++ {I_SYNC, "I_SYNC"}, \
> > > > ++ {I_DIRTY_TIME, "I_DIRTY_TIME"}, \
> > > > ++ {I_REFERENCED, "I_REFERENCED"} \
> > > > ++ )
> > > > ++#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0))
> > > > + #define show_inode_state(state)
> > > > \
> > > > + __print_flags(state, "|", \
> > > > + {I_DIRTY_SYNC, "I_DIRTY_SYNC"}, \
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0008-fix-writeback-Fix-sync-livelock-due-to-b_dirty_time-.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0008-fix-writeback-Fix-sync-livelock-due-to-b_dirty_time-.patch
> > > > new file mode 100644
> > > > index 0000000000..7a0d9a38b8
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0008-fix-writeback-Fix-sync-livelock-due-to-b_dirty_time-.patch
> > > > @@ -0,0 +1,117 @@
> > > > +From 87b2affc3eb06f3fb2d0923f18af37713eb6814b Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Mon, 31 Aug 2020 14:16:01 -0400
> > > > +Subject: [PATCH 08/10] fix: writeback: Fix sync livelock due to
> > > > b_dirty_time
> > > > + processing (v5.9)
> > > > +
> > > > +See upstream commit:
> > > > +
> > > > + commit f9cae926f35e8230330f28c7b743ad088611a8de
> > > > + Author: Jan Kara <j...@suse.cz>
> > > > + Date: Fri May 29 16:08:58 2020 +0200
> > > > +
> > > > + writeback: Fix sync livelock due to b_dirty_time processing
> > > > +
> > > > + When we are processing writeback for sync(2), move_expired_inodes()
> > > > + didn't set any inode expiry value (older_than_this). This can
> > > > result in
> > > > + writeback never completing if there's steady stream of inodes
> > > > added to
> > > > + b_dirty_time list as writeback rechecks dirty lists after each
> > > > writeback
> > > > + round whether there's more work to be done. Fix the problem by
> > > > using
> > > > + sync(2) start time is inode expiry value when processing
> > > > b_dirty_time
> > > > + list similarly as for ordinarily dirtied inodes. This requires some
> > > > + refactoring of older_than_this handling which simplifies the code
> > > > + noticeably as a bonus.
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Change-Id: I8b894b13ccc14d9b8983ee4c2810a927c319560b
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + .../events/lttng-module/writeback.h | 39 ++++++++++++-------
> > > > + 1 file changed, 26 insertions(+), 13 deletions(-)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/writeback.h
> > > > b/instrumentation/events/lttng-module/writeback.h
> > > > +index ece67ad..e9018dd 100644
> > > > +--- a/instrumentation/events/lttng-module/writeback.h
> > > > ++++ b/instrumentation/events/lttng-module/writeback.h
> > > > +@@ -384,34 +384,48 @@
> > > > LTTNG_TRACEPOINT_EVENT_WBC_INSTANCE(wbc_balance_dirty_wait,
> > > > writeback_wbc_balanc
> > > > + #endif
> > > > + LTTNG_TRACEPOINT_EVENT_WBC_INSTANCE(wbc_writepage,
> > > > writeback_wbc_writepage)
> > > > +
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0))
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++LTTNG_TRACEPOINT_EVENT(writeback_queue_io,
> > > > ++ TP_PROTO(struct bdi_writeback *wb,
> > > > ++ struct wb_writeback_work *work,
> > > > ++ unsigned long dirtied_before,
> > > > ++ int moved),
> > > > ++ TP_ARGS(wb, work, dirtied_before, moved),
> > > > ++ TP_FIELDS(
> > > > ++ ctf_array_text(char, name, dev_name(wb->bdi->dev), 32)
> > > > ++ ctf_integer(unsigned long, older, dirtied_before)
> > > > ++ ctf_integer(int, moved, moved)
> > > > ++ )
> > > > ++)
> > > > ++#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))
> > > > + LTTNG_TRACEPOINT_EVENT(writeback_queue_io,
> > > > + TP_PROTO(struct bdi_writeback *wb,
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))
> > > > + struct wb_writeback_work *work,
> > > > +-#else
> > > > +- unsigned long *older_than_this,
> > > > +-#endif
> > > > + int moved),
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))
> > > > + TP_ARGS(wb, work, moved),
> > > > +-#else
> > > > ++ TP_FIELDS(
> > > > ++ ctf_array_text(char, name, dev_name(wb->bdi->dev), 32)
> > > > ++ ctf_integer(int, moved, moved)
> > > > ++ )
> > > > ++)
> > > > ++#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0))
> > > > ++LTTNG_TRACEPOINT_EVENT(writeback_queue_io,
> > > > ++ TP_PROTO(struct bdi_writeback *wb,
> > > > ++ unsigned long *older_than_this,
> > > > ++ int moved),
> > > > + TP_ARGS(wb, older_than_this, moved),
> > > > +-#endif
> > > > + TP_FIELDS(
> > > > + ctf_array_text(char, name, dev_name(wb->bdi->dev), 32)
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))
> > > > +-#else
> > > > + ctf_integer(unsigned long, older,
> > > > + older_than_this ? *older_than_this : 0)
> > > > + ctf_integer(long, age,
> > > > + older_than_this ?
> > > > + (jiffies - *older_than_this) * 1000 / HZ
> > > > + : -1)
> > > > +-#endif
> > > > + ctf_integer(int, moved, moved)
> > > > + )
> > > > + )
> > > > ++#endif
> > > > +
> > > > + #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,8,0))
> > > > + LTTNG_TRACEPOINT_EVENT_MAP(global_dirty_state,
> > > > +@@ -460,7 +474,7 @@ LTTNG_TRACEPOINT_EVENT_MAP(global_dirty_state,
> > > > + ctf_integer(unsigned long, dirty_limit,
> > > > global_dirty_limit)
> > > > + )
> > > > + )
> > > > +-#else
> > > > ++#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0))
> > > > + LTTNG_TRACEPOINT_EVENT_MAP(global_dirty_state,
> > > > +
> > > > + writeback_global_dirty_state,
> > > > +@@ -485,7 +499,6 @@ LTTNG_TRACEPOINT_EVENT_MAP(global_dirty_state,
> > > > + )
> > > > + )
> > > > + #endif
> > > > +-#endif
> > > > +
> > > > + #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))
> > > > +
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0009-fix-version-ranges-for-ext4_discard_preallocations-a.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0009-fix-version-ranges-for-ext4_discard_preallocations-a.patch
> > > > new file mode 100644
> > > > index 0000000000..346e1d63ad
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0009-fix-version-ranges-for-ext4_discard_preallocations-a.patch
> > > > @@ -0,0 +1,52 @@
> > > > +From b74b25f349e92d7b5bdc8684e406d6a889f13773 Mon Sep 17 00:00:00 2001
> > > > +From: Michael Jeanson <mjean...@efficios.com>
> > > > +Date: Fri, 4 Sep 2020 11:52:51 -0400
> > > > +Subject: [PATCH 09/10] fix: version ranges for
> > > > ext4_discard_preallocations and
> > > > + writeback_queue_io
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Michael Jeanson <mjean...@efficios.com>
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +Change-Id: Id4fa53cb2e713cbda651e1a75deed91013115592
> > > > +---
> > > > + instrumentation/events/lttng-module/ext4.h | 3 ++-
> > > > + instrumentation/events/lttng-module/writeback.h | 8 +++++++-
> > > > + 2 files changed, 9 insertions(+), 2 deletions(-)
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/ext4.h
> > > > b/instrumentation/events/lttng-module/ext4.h
> > > > +index 4476abb..b172c8d 100644
> > > > +--- a/instrumentation/events/lttng-module/ext4.h
> > > > ++++ b/instrumentation/events/lttng-module/ext4.h
> > > > +@@ -460,7 +460,8 @@ LTTNG_TRACEPOINT_EVENT(ext4_mb_release_group_pa,
> > > > + )
> > > > + #endif
> > > > +
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(5,8,6, 5,9,0))
> > > > + LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
> > > > + TP_PROTO(struct inode *inode, unsigned int len, unsigned int
> > > > needed),
> > > > +
> > > > +diff --git a/instrumentation/events/lttng-module/writeback.h
> > > > b/instrumentation/events/lttng-module/writeback.h
> > > > +index e9018dd..09637d7 100644
> > > > +--- a/instrumentation/events/lttng-module/writeback.h
> > > > ++++ b/instrumentation/events/lttng-module/writeback.h
> > > > +@@ -384,7 +384,13 @@
> > > > LTTNG_TRACEPOINT_EVENT_WBC_INSTANCE(wbc_balance_dirty_wait,
> > > > writeback_wbc_balanc
> > > > + #endif
> > > > + LTTNG_TRACEPOINT_EVENT_WBC_INSTANCE(wbc_writepage,
> > > > writeback_wbc_writepage)
> > > > +
> > > > +-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
> > > > ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(5,8,6, 5,9,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(5,4,62, 5,5,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(4,19,143, 4,20,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(4,14,196, 4,15,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(4,9,235, 4,10,0) || \
> > > > ++ LTTNG_KERNEL_RANGE(4,4,235, 4,5,0))
> > > > + LTTNG_TRACEPOINT_EVENT(writeback_queue_io,
> > > > + TP_PROTO(struct bdi_writeback *wb,
> > > > + struct wb_writeback_work *work,
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git
> > > > a/meta/recipes-kernel/lttng/lttng-modules/0010-Fix-system-call-filter-table.patch
> > > >
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0010-Fix-system-call-filter-table.patch
> > > > new file mode 100644
> > > > index 0000000000..a16750ddb3
> > > > --- /dev/null
> > > > +++
> > > > b/meta/recipes-kernel/lttng/lttng-modules/0010-Fix-system-call-filter-table.patch
> > > > @@ -0,0 +1,918 @@
> > > > +From ad594e3a953db1b0c3c059fde45b5a5494f6be78 Mon Sep 17 00:00:00 2001
> > > > +From: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +Date: Tue, 28 Jan 2020 16:02:44 -0500
> > > > +Subject: [PATCH 10/10] Fix: system call filter table
> > > > +
> > > > +The system call filter table has effectively been unused for a long
> > > > +time due to system call name prefix mismatch. This means the overhead
> > > > of
> > > > +selective system call tracing was larger than it should have been
> > > > because
> > > > +the event payload preparation would be done for all system calls as
> > > > soon
> > > > +as a single system call is traced.
> > > > +
> > > > +However, fixing this underlying issue unearths several issues that
> > > > crept
> > > > +unnoticed when the "enabler" concept was introduced (after the original
> > > > +implementation of the system call filter table).
> > > > +
> > > > +Here is a list of the issues which are resolved here:
> > > > +
> > > > +- Split lttng_syscalls_unregister into an unregister and destroy
> > > > + function, thus awaiting for a grace period (and therefore quiescence
> > > > + of the users) after unregistering the system call tracepoints before
> > > > + freeing the system call filter data structures. This effectively
> > > > fixes
> > > > + a use-after-free.
> > > > +
> > > > +- The state for enabling "all" system calls vs enabling specific system
> > > > + calls (and sequences of enable-disable) was incorrect with respect to
> > > > + the "enablers" semantic. This is solved by always tracking the
> > > > + bitmap of enabled system calls, and keeping this bitmap even when
> > > > + enabling all system calls. The sc_filter is now always allocated
> > > > + before system call tracing is registered to tracepoints, which means
> > > > + it does not need to be RCU dereferenced anymore.
> > > > +
> > > > +Padding fields in the ABI are reserved to select whether to:
> > > > +
> > > > +- Trace either native or compat system call (or both, which is the
> > > > + behavior currently implemented),
> > > > +- Trace either system call entry or exit (or both, which is the
> > > > + behavior currently implemented),
> > > > +- Select the system call to trace by name (behavior currently
> > > > + implemented) or by system call number,
> > > > +
> > > > +Upstream-Status: Backport
> > > > +
> > > > +Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> > > > +---
> > > > + lttng-abi.c | 43 ++++++
> > > > + lttng-abi.h | 26 ++++
> > > > + lttng-events.c | 112 +++++++++++++--
> > > > + lttng-events.h | 31 ++++-
> > > > + lttng-syscalls.c | 348 +++++++++++++++++++++++++----------------------
> > > > + 5 files changed, 380 insertions(+), 180 deletions(-)
> > > > +
> > > > +diff --git a/lttng-abi.c b/lttng-abi.c
> > > > +index 64ea99d..b33879d 100644
> > > > +--- a/lttng-abi.c
> > > > ++++ b/lttng-abi.c
> > > > +@@ -1264,6 +1264,46 @@ nomem:
> > > > + return ret;
> > > > + }
> > > > +
> > > > ++static
> > > > ++int lttng_abi_validate_event_param(struct lttng_kernel_event
> > > > *event_param)
> > > > ++{
> > > > ++ /* Limit ABI to implemented features. */
> > > > ++ switch (event_param->instrumentation) {
> > > > ++ case LTTNG_KERNEL_SYSCALL:
> > > > ++ switch (event_param->u.syscall.entryexit) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ switch (event_param->u.syscall.abi) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_ALL:
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ switch (event_param->u.syscall.match) {
> > > > ++ case LTTNG_SYSCALL_MATCH_NAME:
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ break;
> > > > ++
> > > > ++ case LTTNG_KERNEL_TRACEPOINT: /* Fallthrough */
> > > > ++ case LTTNG_KERNEL_KPROBE: /* Fallthrough */
> > > > ++ case LTTNG_KERNEL_KRETPROBE: /* Fallthrough */
> > > > ++ case LTTNG_KERNEL_NOOP: /* Fallthrough */
> > > > ++ case LTTNG_KERNEL_UPROBE:
> > > > ++ break;
> > > > ++
> > > > ++ case LTTNG_KERNEL_FUNCTION: /* Fallthrough */
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ return 0;
> > > > ++}
> > > > ++
> > > > + static
> > > > + int lttng_abi_create_event(struct file *channel_file,
> > > > + struct lttng_kernel_event *event_param)
> > > > +@@ -1305,6 +1345,9 @@ int lttng_abi_create_event(struct file
> > > > *channel_file,
> > > > + ret = -EOVERFLOW;
> > > > + goto refcount_error;
> > > > + }
> > > > ++ ret = lttng_abi_validate_event_param(event_param);
> > > > ++ if (ret)
> > > > ++ goto event_error;
> > > > + if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
> > > > + || event_param->instrumentation ==
> > > > LTTNG_KERNEL_SYSCALL) {
> > > > + struct lttng_enabler *enabler;
> > > > +diff --git a/lttng-abi.h b/lttng-abi.h
> > > > +index 1d356ab..51d60e5 100644
> > > > +--- a/lttng-abi.h
> > > > ++++ b/lttng-abi.h
> > > > +@@ -90,6 +90,31 @@ struct lttng_kernel_event_callsite {
> > > > + } u;
> > > > + } __attribute__((packed));
> > > > +
> > > > ++enum lttng_kernel_syscall_entryexit {
> > > > ++ LTTNG_KERNEL_SYSCALL_ENTRYEXIT = 0,
> > > > ++ LTTNG_KERNEL_SYSCALL_ENTRY = 1, /* Not implemented. */
> > > > ++ LTTNG_KERNEL_SYSCALL_EXIT = 2, /* Not implemented. */
> > > > ++};
> > > > ++
> > > > ++enum lttng_kernel_syscall_abi {
> > > > ++ LTTNG_KERNEL_SYSCALL_ABI_ALL = 0,
> > > > ++ LTTNG_KERNEL_SYSCALL_ABI_NATIVE = 1, /* Not implemented. */
> > > > ++ LTTNG_KERNEL_SYSCALL_ABI_COMPAT = 2, /* Not implemented. */
> > > > ++};
> > > > ++
> > > > ++enum lttng_kernel_syscall_match {
> > > > ++ LTTNG_SYSCALL_MATCH_NAME = 0,
> > > > ++ LTTNG_SYSCALL_MATCH_NR = 1, /* Not implemented. */
> > > > ++};
> > > > ++
> > > > ++struct lttng_kernel_syscall {
> > > > ++ uint8_t entryexit; /* enum lttng_kernel_syscall_entryexit
> > > > */
> > > > ++ uint8_t abi; /* enum lttng_kernel_syscall_abi */
> > > > ++ uint8_t match; /* enum lttng_kernel_syscall_match */
> > > > ++ uint8_t padding;
> > > > ++ uint32_t nr; /* For LTTNG_SYSCALL_MATCH_NR */
> > > > ++} __attribute__((packed));
> > > > ++
> > > > + /*
> > > > + * For syscall tracing, name = "*" means "enable all".
> > > > + */
> > > > +@@ -106,6 +131,7 @@ struct lttng_kernel_event {
> > > > + struct lttng_kernel_kprobe kprobe;
> > > > + struct lttng_kernel_function_tracer ftrace;
> > > > + struct lttng_kernel_uprobe uprobe;
> > > > ++ struct lttng_kernel_syscall syscall;
> > > > + char padding[LTTNG_KERNEL_EVENT_PADDING2];
> > > > + } u;
> > > > + } __attribute__((packed));
> > > > +diff --git a/lttng-events.c b/lttng-events.c
> > > > +index d719294..4c0b04a 100644
> > > > +--- a/lttng-events.c
> > > > ++++ b/lttng-events.c
> > > > +@@ -201,6 +201,10 @@ void lttng_session_destroy(struct lttng_session
> > > > *session)
> > > > + WARN_ON(ret);
> > > > + }
> > > > + synchronize_trace(); /* Wait for in-flight events to
> > > > complete */
> > > > ++ list_for_each_entry(chan, &session->chan, list) {
> > > > ++ ret = lttng_syscalls_destroy(chan);
> > > > ++ WARN_ON(ret);
> > > > ++ }
> > > > + list_for_each_entry_safe(enabler, tmpenabler,
> > > > + &session->enablers_head, node)
> > > > + lttng_enabler_destroy(enabler);
> > > > +@@ -740,6 +744,28 @@ struct lttng_event *_lttng_event_create(struct
> > > > lttng_channel *chan,
> > > > + event->enabled = 0;
> > > > + event->registered = 0;
> > > > + event->desc = event_desc;
> > > > ++ switch (event_param->u.syscall.entryexit) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
> > > > ++ ret = -EINVAL;
> > > > ++ goto register_error;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ENTRY:
> > > > ++ event->u.syscall.entryexit =
> > > > LTTNG_SYSCALL_ENTRY;
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_EXIT:
> > > > ++ event->u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
> > > > ++ break;
> > > > ++ }
> > > > ++ switch (event_param->u.syscall.abi) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_ALL:
> > > > ++ ret = -EINVAL;
> > > > ++ goto register_error;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
> > > > ++ event->u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
> > > > ++ event->u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
> > > > ++ break;
> > > > ++ }
> > > > + if (!event->desc) {
> > > > + ret = -EINVAL;
> > > > + goto register_error;
> > > > +@@ -826,8 +852,7 @@ void register_event(struct lttng_event *event)
> > > > + event);
> > > > + break;
> > > > + case LTTNG_KERNEL_SYSCALL:
> > > > +- ret = lttng_syscall_filter_enable(event->chan,
> > > > +- desc->name);
> > > > ++ ret = lttng_syscall_filter_enable(event->chan, event);
> > > > + break;
> > > > + case LTTNG_KERNEL_KPROBE:
> > > > + case LTTNG_KERNEL_UPROBE:
> > > > +@@ -870,8 +895,7 @@ int _lttng_event_unregister(struct lttng_event
> > > > *event)
> > > > + ret = 0;
> > > > + break;
> > > > + case LTTNG_KERNEL_SYSCALL:
> > > > +- ret = lttng_syscall_filter_disable(event->chan,
> > > > +- desc->name);
> > > > ++ ret = lttng_syscall_filter_disable(event->chan, event);
> > > > + break;
> > > > + case LTTNG_KERNEL_NOOP:
> > > > + ret = 0;
> > > > +@@ -1203,39 +1227,87 @@ int lttng_desc_match_enabler(const struct
> > > > lttng_event_desc *desc,
> > > > + struct lttng_enabler *enabler)
> > > > + {
> > > > + const char *desc_name, *enabler_name;
> > > > ++ bool compat = false, entry = false;
> > > > +
> > > > + enabler_name = enabler->event_param.name;
> > > > + switch (enabler->event_param.instrumentation) {
> > > > + case LTTNG_KERNEL_TRACEPOINT:
> > > > + desc_name = desc->name;
> > > > ++ switch (enabler->type) {
> > > > ++ case LTTNG_ENABLER_STAR_GLOB:
> > > > ++ return lttng_match_enabler_star_glob(desc_name,
> > > > enabler_name);
> > > > ++ case LTTNG_ENABLER_NAME:
> > > > ++ return lttng_match_enabler_name(desc_name,
> > > > enabler_name);
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > + break;
> > > > + case LTTNG_KERNEL_SYSCALL:
> > > > + desc_name = desc->name;
> > > > +- if (!strncmp(desc_name, "compat_", strlen("compat_")))
> > > > ++ if (!strncmp(desc_name, "compat_", strlen("compat_"))) {
> > > > + desc_name += strlen("compat_");
> > > > ++ compat = true;
> > > > ++ }
> > > > + if (!strncmp(desc_name, "syscall_exit_",
> > > > + strlen("syscall_exit_"))) {
> > > > + desc_name += strlen("syscall_exit_");
> > > > + } else if (!strncmp(desc_name, "syscall_entry_",
> > > > + strlen("syscall_entry_"))) {
> > > > + desc_name += strlen("syscall_entry_");
> > > > ++ entry = true;
> > > > + } else {
> > > > + WARN_ON_ONCE(1);
> > > > + return -EINVAL;
> > > > + }
> > > > ++ switch (enabler->event_param.u.syscall.entryexit) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ENTRY:
> > > > ++ if (!entry)
> > > > ++ return 0;
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_EXIT:
> > > > ++ if (entry)
> > > > ++ return 0;
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ switch (enabler->event_param.u.syscall.abi) {
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_ALL:
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_NATIVE:
> > > > ++ if (compat)
> > > > ++ return 0;
> > > > ++ break;
> > > > ++ case LTTNG_KERNEL_SYSCALL_ABI_COMPAT:
> > > > ++ if (!compat)
> > > > ++ return 0;
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ switch (enabler->event_param.u.syscall.match) {
> > > > ++ case LTTNG_SYSCALL_MATCH_NAME:
> > > > ++ switch (enabler->type) {
> > > > ++ case LTTNG_ENABLER_STAR_GLOB:
> > > > ++ return
> > > > lttng_match_enabler_star_glob(desc_name, enabler_name);
> > > > ++ case LTTNG_ENABLER_NAME:
> > > > ++ return
> > > > lttng_match_enabler_name(desc_name, enabler_name);
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_MATCH_NR:
> > > > ++ return -EINVAL; /* Not implemented. */
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > ++ }
> > > > + break;
> > > > + default:
> > > > + WARN_ON_ONCE(1);
> > > > + return -EINVAL;
> > > > + }
> > > > +- switch (enabler->type) {
> > > > +- case LTTNG_ENABLER_STAR_GLOB:
> > > > +- return lttng_match_enabler_star_glob(desc_name,
> > > > enabler_name);
> > > > +- case LTTNG_ENABLER_NAME:
> > > > +- return lttng_match_enabler_name(desc_name,
> > > > enabler_name);
> > > > +- default:
> > > > +- return -EINVAL;
> > > > +- }
> > > > + }
> > > > +
> > > > + static
> > > > +@@ -1361,9 +1433,21 @@ void lttng_create_event_if_missing(struct
> > > > lttng_enabler *enabler)
> > > > + static
> > > > + int lttng_enabler_ref_events(struct lttng_enabler *enabler)
> > > > + {
> > > > +- struct lttng_session *session = enabler->chan->session;
> > > > ++ struct lttng_channel *chan = enabler->chan;
> > > > ++ struct lttng_session *session = chan->session;
> > > > + struct lttng_event *event;
> > > > +
> > > > ++ if (enabler->event_param.instrumentation ==
> > > > LTTNG_KERNEL_SYSCALL &&
> > > > ++ enabler->event_param.u.syscall.entryexit ==
> > > > LTTNG_KERNEL_SYSCALL_ENTRYEXIT &&
> > > > ++ enabler->event_param.u.syscall.abi ==
> > > > LTTNG_KERNEL_SYSCALL_ABI_ALL &&
> > > > ++ enabler->event_param.u.syscall.match ==
> > > > LTTNG_SYSCALL_MATCH_NAME &&
> > > > ++ !strcmp(enabler->event_param.name, "*")) {
> > > > ++ if (enabler->enabled)
> > > > ++ WRITE_ONCE(chan->syscall_all, 1);
> > > > ++ else
> > > > ++ WRITE_ONCE(chan->syscall_all, 0);
> > > > ++ }
> > > > ++
> > > > + /* First ensure that probe events are created for this enabler.
> > > > */
> > > > + lttng_create_event_if_missing(enabler);
> > > > +
> > > > +diff --git a/lttng-events.h b/lttng-events.h
> > > > +index a36a312..d4d9976 100644
> > > > +--- a/lttng-events.h
> > > > ++++ b/lttng-events.h
> > > > +@@ -292,6 +292,16 @@ struct lttng_uprobe_handler {
> > > > + struct list_head node;
> > > > + };
> > > > +
> > > > ++enum lttng_syscall_entryexit {
> > > > ++ LTTNG_SYSCALL_ENTRY,
> > > > ++ LTTNG_SYSCALL_EXIT,
> > > > ++};
> > > > ++
> > > > ++enum lttng_syscall_abi {
> > > > ++ LTTNG_SYSCALL_ABI_NATIVE,
> > > > ++ LTTNG_SYSCALL_ABI_COMPAT,
> > > > ++};
> > > > ++
> > > > + /*
> > > > + * lttng_event structure is referred to by the tracing fast path. It
> > > > must be
> > > > + * kept small.
> > > > +@@ -318,6 +328,11 @@ struct lttng_event {
> > > > + struct inode *inode;
> > > > + struct list_head head;
> > > > + } uprobe;
> > > > ++ struct {
> > > > ++ char *syscall_name;
> > > > ++ enum lttng_syscall_entryexit entryexit;
> > > > ++ enum lttng_syscall_abi abi;
> > > > ++ } syscall;
> > > > + } u;
> > > > + struct list_head list; /* Event list in session */
> > > > + unsigned int metadata_dumped:1;
> > > > +@@ -457,10 +472,10 @@ struct lttng_channel {
> > > > + struct lttng_syscall_filter *sc_filter;
> > > > + int header_type; /* 0: unset, 1: compact, 2:
> > > > large */
> > > > + enum channel_type channel_type;
> > > > ++ int syscall_all;
> > > > + unsigned int metadata_dumped:1,
> > > > + sys_enter_registered:1,
> > > > + sys_exit_registered:1,
> > > > +- syscall_all:1,
> > > > + tstate:1; /* Transient enable state */
> > > > + };
> > > > +
> > > > +@@ -653,10 +668,11 @@ void lttng_clock_unref(void);
> > > > + #if defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
> > > > + int lttng_syscalls_register(struct lttng_channel *chan, void *filter);
> > > > + int lttng_syscalls_unregister(struct lttng_channel *chan);
> > > > ++int lttng_syscalls_destroy(struct lttng_channel *chan);
> > > > + int lttng_syscall_filter_enable(struct lttng_channel *chan,
> > > > +- const char *name);
> > > > ++ struct lttng_event *event);
> > > > + int lttng_syscall_filter_disable(struct lttng_channel *chan,
> > > > +- const char *name);
> > > > ++ struct lttng_event *event);
> > > > + long lttng_channel_syscall_mask(struct lttng_channel *channel,
> > > > + struct lttng_kernel_syscall_mask __user *usyscall_mask);
> > > > + #else
> > > > +@@ -670,14 +686,19 @@ static inline int
> > > > lttng_syscalls_unregister(struct lttng_channel *chan)
> > > > + return 0;
> > > > + }
> > > > +
> > > > ++static inline int lttng_syscalls_destroy(struct lttng_channel *chan)
> > > > ++{
> > > > ++ return 0;
> > > > ++}
> > > > ++
> > > > + static inline int lttng_syscall_filter_enable(struct lttng_channel
> > > > *chan,
> > > > +- const char *name)
> > > > ++ struct lttng_event *event);
> > > > + {
> > > > + return -ENOSYS;
> > > > + }
> > > > +
> > > > + static inline int lttng_syscall_filter_disable(struct lttng_channel
> > > > *chan,
> > > > +- const char *name)
> > > > ++ struct lttng_event *event);
> > > > + {
> > > > + return -ENOSYS;
> > > > + }
> > > > +diff --git a/lttng-syscalls.c b/lttng-syscalls.c
> > > > +index 97f1ba9..26cead6 100644
> > > > +--- a/lttng-syscalls.c
> > > > ++++ b/lttng-syscalls.c
> > > > +@@ -367,8 +367,10 @@ const struct trace_syscall_entry
> > > > compat_sc_exit_table[] = {
> > > > + #undef CREATE_SYSCALL_TABLE
> > > > +
> > > > + struct lttng_syscall_filter {
> > > > +- DECLARE_BITMAP(sc, NR_syscalls);
> > > > +- DECLARE_BITMAP(sc_compat, NR_compat_syscalls);
> > > > ++ DECLARE_BITMAP(sc_entry, NR_syscalls);
> > > > ++ DECLARE_BITMAP(sc_exit, NR_syscalls);
> > > > ++ DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls);
> > > > ++ DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
> > > > + };
> > > > +
> > > > + static void syscall_entry_unknown(struct lttng_event *event,
> > > > +@@ -391,29 +393,23 @@ void syscall_entry_probe(void *__data, struct
> > > > pt_regs *regs, long id)
> > > > + size_t table_len;
> > > > +
> > > > + if (unlikely(in_compat_syscall())) {
> > > > +- struct lttng_syscall_filter *filter;
> > > > +-
> > > > +- filter = lttng_rcu_dereference(chan->sc_filter);
> > > > +- if (filter) {
> > > > +- if (id < 0 || id >= NR_compat_syscalls
> > > > +- || !test_bit(id, filter->sc_compat)) {
> > > > +- /* System call filtered out. */
> > > > +- return;
> > > > +- }
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++
> > > > ++ if (id < 0 || id >= NR_compat_syscalls
> > > > ++ || (!READ_ONCE(chan->syscall_all) &&
> > > > !test_bit(id, filter->sc_compat_entry))) {
> > > > ++ /* System call filtered out. */
> > > > ++ return;
> > > > + }
> > > > + table = compat_sc_table;
> > > > + table_len = ARRAY_SIZE(compat_sc_table);
> > > > + unknown_event = chan->sc_compat_unknown;
> > > > + } else {
> > > > +- struct lttng_syscall_filter *filter;
> > > > +-
> > > > +- filter = lttng_rcu_dereference(chan->sc_filter);
> > > > +- if (filter) {
> > > > +- if (id < 0 || id >= NR_syscalls
> > > > +- || !test_bit(id, filter->sc)) {
> > > > +- /* System call filtered out. */
> > > > +- return;
> > > > +- }
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++
> > > > ++ if (id < 0 || id >= NR_syscalls
> > > > ++ || (!READ_ONCE(chan->syscall_all) &&
> > > > !test_bit(id, filter->sc_entry))) {
> > > > ++ /* System call filtered out. */
> > > > ++ return;
> > > > + }
> > > > + table = sc_table;
> > > > + table_len = ARRAY_SIZE(sc_table);
> > > > +@@ -545,29 +541,23 @@ void syscall_exit_probe(void *__data, struct
> > > > pt_regs *regs, long ret)
> > > > +
> > > > + id = syscall_get_nr(current, regs);
> > > > + if (unlikely(in_compat_syscall())) {
> > > > +- struct lttng_syscall_filter *filter;
> > > > +-
> > > > +- filter = lttng_rcu_dereference(chan->sc_filter);
> > > > +- if (filter) {
> > > > +- if (id < 0 || id >= NR_compat_syscalls
> > > > +- || !test_bit(id, filter->sc_compat)) {
> > > > +- /* System call filtered out. */
> > > > +- return;
> > > > +- }
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++
> > > > ++ if (id < 0 || id >= NR_compat_syscalls
> > > > ++ || (!READ_ONCE(chan->syscall_all) &&
> > > > !test_bit(id, filter->sc_compat_exit))) {
> > > > ++ /* System call filtered out. */
> > > > ++ return;
> > > > + }
> > > > + table = compat_sc_exit_table;
> > > > + table_len = ARRAY_SIZE(compat_sc_exit_table);
> > > > + unknown_event = chan->compat_sc_exit_unknown;
> > > > + } else {
> > > > +- struct lttng_syscall_filter *filter;
> > > > +-
> > > > +- filter = lttng_rcu_dereference(chan->sc_filter);
> > > > +- if (filter) {
> > > > +- if (id < 0 || id >= NR_syscalls
> > > > +- || !test_bit(id, filter->sc)) {
> > > > +- /* System call filtered out. */
> > > > +- return;
> > > > +- }
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++
> > > > ++ if (id < 0 || id >= NR_syscalls
> > > > ++ || (!READ_ONCE(chan->syscall_all) &&
> > > > !test_bit(id, filter->sc_exit))) {
> > > > ++ /* System call filtered out. */
> > > > ++ return;
> > > > + }
> > > > + table = sc_exit_table;
> > > > + table_len = ARRAY_SIZE(sc_exit_table);
> > > > +@@ -713,27 +703,23 @@ int fill_table(const struct trace_syscall_entry
> > > > *table, size_t table_len,
> > > > + memset(&ev, 0, sizeof(ev));
> > > > + switch (type) {
> > > > + case SC_TYPE_ENTRY:
> > > > +- strncpy(ev.name, SYSCALL_ENTRY_STR,
> > > > +- LTTNG_KERNEL_SYM_NAME_LEN);
> > > > ++ ev.u.syscall.entryexit =
> > > > LTTNG_KERNEL_SYSCALL_ENTRY;
> > > > ++ ev.u.syscall.abi =
> > > > LTTNG_KERNEL_SYSCALL_ABI_NATIVE;
> > > > + break;
> > > > + case SC_TYPE_EXIT:
> > > > +- strncpy(ev.name, SYSCALL_EXIT_STR,
> > > > +- LTTNG_KERNEL_SYM_NAME_LEN);
> > > > ++ ev.u.syscall.entryexit =
> > > > LTTNG_KERNEL_SYSCALL_EXIT;
> > > > ++ ev.u.syscall.abi =
> > > > LTTNG_KERNEL_SYSCALL_ABI_NATIVE;
> > > > + break;
> > > > + case SC_TYPE_COMPAT_ENTRY:
> > > > +- strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR,
> > > > +- LTTNG_KERNEL_SYM_NAME_LEN);
> > > > ++ ev.u.syscall.entryexit =
> > > > LTTNG_KERNEL_SYSCALL_ENTRY;
> > > > ++ ev.u.syscall.abi =
> > > > LTTNG_KERNEL_SYSCALL_ABI_COMPAT;
> > > > + break;
> > > > + case SC_TYPE_COMPAT_EXIT:
> > > > +- strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR,
> > > > +- LTTNG_KERNEL_SYM_NAME_LEN);
> > > > +- break;
> > > > +- default:
> > > > +- BUG_ON(1);
> > > > ++ ev.u.syscall.entryexit =
> > > > LTTNG_KERNEL_SYSCALL_EXIT;
> > > > ++ ev.u.syscall.abi =
> > > > LTTNG_KERNEL_SYSCALL_ABI_COMPAT;
> > > > + break;
> > > > + }
> > > > +- strncat(ev.name, desc->name,
> > > > +- LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) -
> > > > 1);
> > > > ++ strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
> > > > + ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
> > > > + ev.instrumentation = LTTNG_KERNEL_SYSCALL;
> > > > + chan_table[i] = _lttng_event_create(chan, &ev, filter,
> > > > +@@ -803,6 +789,8 @@ int lttng_syscalls_register(struct lttng_channel
> > > > *chan, void *filter)
> > > > + strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
> > > > + ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
> > > > + ev.instrumentation = LTTNG_KERNEL_SYSCALL;
> > > > ++ ev.u.syscall.entryexit = LTTNG_KERNEL_SYSCALL_ENTRY;
> > > > ++ ev.u.syscall.abi = LTTNG_KERNEL_SYSCALL_ABI_NATIVE;
> > > > + chan->sc_unknown = _lttng_event_create(chan, &ev,
> > > > filter,
> > > > + desc,
> > > > + ev.instrumentation);
> > > > +@@ -820,6 +808,8 @@ int lttng_syscalls_register(struct lttng_channel
> > > > *chan, void *filter)
> > > > + strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
> > > > + ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
> > > > + ev.instrumentation = LTTNG_KERNEL_SYSCALL;
> > > > ++ ev.u.syscall.entryexit = LTTNG_KERNEL_SYSCALL_ENTRY;
> > > > ++ ev.u.syscall.abi = LTTNG_KERNEL_SYSCALL_ABI_COMPAT;
> > > > + chan->sc_compat_unknown = _lttng_event_create(chan,
> > > > &ev, filter,
> > > > + desc,
> > > > + ev.instrumentation);
> > > > +@@ -837,6 +827,8 @@ int lttng_syscalls_register(struct lttng_channel
> > > > *chan, void *filter)
> > > > + strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
> > > > + ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
> > > > + ev.instrumentation = LTTNG_KERNEL_SYSCALL;
> > > > ++ ev.u.syscall.entryexit = LTTNG_KERNEL_SYSCALL_EXIT;
> > > > ++ ev.u.syscall.abi = LTTNG_KERNEL_SYSCALL_ABI_COMPAT;
> > > > + chan->compat_sc_exit_unknown =
> > > > _lttng_event_create(chan, &ev,
> > > > + filter, desc,
> > > > + ev.instrumentation);
> > > > +@@ -854,6 +846,8 @@ int lttng_syscalls_register(struct lttng_channel
> > > > *chan, void *filter)
> > > > + strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
> > > > + ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
> > > > + ev.instrumentation = LTTNG_KERNEL_SYSCALL;
> > > > ++ ev.u.syscall.entryexit = LTTNG_KERNEL_SYSCALL_EXIT;
> > > > ++ ev.u.syscall.abi = LTTNG_KERNEL_SYSCALL_ABI_NATIVE;
> > > > + chan->sc_exit_unknown = _lttng_event_create(chan, &ev,
> > > > filter,
> > > > + desc,
> > > > ev.instrumentation);
> > > > + WARN_ON_ONCE(!chan->sc_exit_unknown);
> > > > +@@ -883,6 +877,14 @@ int lttng_syscalls_register(struct lttng_channel
> > > > *chan, void *filter)
> > > > + if (ret)
> > > > + return ret;
> > > > + #endif
> > > > ++
> > > > ++ if (!chan->sc_filter) {
> > > > ++ chan->sc_filter = kzalloc(sizeof(struct
> > > > lttng_syscall_filter),
> > > > ++ GFP_KERNEL);
> > > > ++ if (!chan->sc_filter)
> > > > ++ return -ENOMEM;
> > > > ++ }
> > > > ++
> > > > + if (!chan->sys_enter_registered) {
> > > > + ret =
> > > > lttng_wrapper_tracepoint_probe_register("sys_enter",
> > > > + (void *) syscall_entry_probe, chan);
> > > > +@@ -930,7 +932,11 @@ int lttng_syscalls_unregister(struct
> > > > lttng_channel *chan)
> > > > + return ret;
> > > > + chan->sys_exit_registered = 0;
> > > > + }
> > > > +- /* lttng_event destroy will be performed by
> > > > lttng_session_destroy() */
> > > > ++ return 0;
> > > > ++}
> > > > ++
> > > > ++int lttng_syscalls_destroy(struct lttng_channel *chan)
> > > > ++{
> > > > + kfree(chan->sc_table);
> > > > + kfree(chan->sc_exit_table);
> > > > + #ifdef CONFIG_COMPAT
> > > > +@@ -993,136 +999,150 @@ uint32_t get_sc_tables_len(void)
> > > > + return ARRAY_SIZE(sc_table) + ARRAY_SIZE(compat_sc_table);
> > > > + }
> > > > +
> > > > +-int lttng_syscall_filter_enable(struct lttng_channel *chan,
> > > > +- const char *name)
> > > > ++static
> > > > ++const char *get_syscall_name(struct lttng_event *event)
> > > > + {
> > > > +- int syscall_nr, compat_syscall_nr, ret;
> > > > +- struct lttng_syscall_filter *filter;
> > > > ++ size_t prefix_len = 0;
> > > > +
> > > > +- WARN_ON_ONCE(!chan->sc_table);
> > > > ++ WARN_ON_ONCE(event->instrumentation != LTTNG_KERNEL_SYSCALL);
> > > > +
> > > > +- if (!name) {
> > > > +- /* Enable all system calls by removing filter */
> > > > +- if (chan->sc_filter) {
> > > > +- filter = chan->sc_filter;
> > > > +- rcu_assign_pointer(chan->sc_filter, NULL);
> > > > +- synchronize_trace();
> > > > +- kfree(filter);
> > > > ++ switch (event->u.syscall.entryexit) {
> > > > ++ case LTTNG_SYSCALL_ENTRY:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ prefix_len = strlen(SYSCALL_ENTRY_STR);
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
> > > > ++ break;
> > > > + }
> > > > +- chan->syscall_all = 1;
> > > > +- return 0;
> > > > +- }
> > > > +-
> > > > +- if (!chan->sc_filter) {
> > > > +- if (chan->syscall_all) {
> > > > +- /*
> > > > +- * All syscalls are already enabled.
> > > > +- */
> > > > +- return -EEXIST;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_EXIT:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ prefix_len = strlen(SYSCALL_EXIT_STR);
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
> > > > ++ break;
> > > > + }
> > > > +- filter = kzalloc(sizeof(struct lttng_syscall_filter),
> > > > +- GFP_KERNEL);
> > > > +- if (!filter)
> > > > +- return -ENOMEM;
> > > > +- } else {
> > > > +- filter = chan->sc_filter;
> > > > ++ break;
> > > > + }
> > > > +- syscall_nr = get_syscall_nr(name);
> > > > +- compat_syscall_nr = get_compat_syscall_nr(name);
> > > > +- if (syscall_nr < 0 && compat_syscall_nr < 0) {
> > > > +- ret = -ENOENT;
> > > > +- goto error;
> > > > ++ WARN_ON_ONCE(prefix_len == 0);
> > > > ++ return event->desc->name + prefix_len;
> > > > ++}
> > > > ++
> > > > ++int lttng_syscall_filter_enable(struct lttng_channel *chan,
> > > > ++ struct lttng_event *event)
> > > > ++{
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++ const char *syscall_name;
> > > > ++ unsigned long *bitmap;
> > > > ++ int syscall_nr;
> > > > ++
> > > > ++ WARN_ON_ONCE(!chan->sc_table);
> > > > ++
> > > > ++ syscall_name = get_syscall_name(event);
> > > > ++
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ syscall_nr = get_syscall_nr(syscall_name);
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ syscall_nr = get_compat_syscall_nr(syscall_name);
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > + }
> > > > +- if (syscall_nr >= 0) {
> > > > +- if (test_bit(syscall_nr, filter->sc)) {
> > > > +- ret = -EEXIST;
> > > > +- goto error;
> > > > ++ if (syscall_nr < 0)
> > > > ++ return -ENOENT;
> > > > ++
> > > > ++
> > > > ++ switch (event->u.syscall.entryexit) {
> > > > ++ case LTTNG_SYSCALL_ENTRY:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ bitmap = filter->sc_entry;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ bitmap = filter->sc_compat_entry;
> > > > ++ break;
> > > > + }
> > > > +- bitmap_set(filter->sc, syscall_nr, 1);
> > > > +- }
> > > > +- if (compat_syscall_nr >= 0) {
> > > > +- if (test_bit(compat_syscall_nr, filter->sc_compat)) {
> > > > +- ret = -EEXIST;
> > > > +- goto error;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_EXIT:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ bitmap = filter->sc_exit;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ bitmap = filter->sc_compat_exit;
> > > > ++ break;
> > > > + }
> > > > +- bitmap_set(filter->sc_compat, compat_syscall_nr, 1);
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > + }
> > > > +- if (!chan->sc_filter)
> > > > +- rcu_assign_pointer(chan->sc_filter, filter);
> > > > ++ if (test_bit(syscall_nr, bitmap))
> > > > ++ return -EEXIST;
> > > > ++ bitmap_set(bitmap, syscall_nr, 1);
> > > > + return 0;
> > > > +-
> > > > +-error:
> > > > +- if (!chan->sc_filter)
> > > > +- kfree(filter);
> > > > +- return ret;
> > > > + }
> > > > +
> > > > + int lttng_syscall_filter_disable(struct lttng_channel *chan,
> > > > +- const char *name)
> > > > ++ struct lttng_event *event)
> > > > + {
> > > > +- int syscall_nr, compat_syscall_nr, ret;
> > > > +- struct lttng_syscall_filter *filter;
> > > > ++ struct lttng_syscall_filter *filter = chan->sc_filter;
> > > > ++ const char *syscall_name;
> > > > ++ unsigned long *bitmap;
> > > > ++ int syscall_nr;
> > > > +
> > > > + WARN_ON_ONCE(!chan->sc_table);
> > > > +
> > > > +- if (!chan->sc_filter) {
> > > > +- if (!chan->syscall_all)
> > > > +- return -EEXIST;
> > > > +- filter = kzalloc(sizeof(struct lttng_syscall_filter),
> > > > +- GFP_KERNEL);
> > > > +- if (!filter)
> > > > +- return -ENOMEM;
> > > > +- /* Trace all system calls, then apply disable. */
> > > > +- bitmap_set(filter->sc, 0, NR_syscalls);
> > > > +- bitmap_set(filter->sc_compat, 0, NR_compat_syscalls);
> > > > +- } else {
> > > > +- filter = chan->sc_filter;
> > > > ++ syscall_name = get_syscall_name(event);
> > > > ++
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ syscall_nr = get_syscall_nr(syscall_name);
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ syscall_nr = get_compat_syscall_nr(syscall_name);
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > + }
> > > > ++ if (syscall_nr < 0)
> > > > ++ return -ENOENT;
> > > > +
> > > > +- if (!name) {
> > > > +- /* Fail if all syscalls are already disabled. */
> > > > +- if (bitmap_empty(filter->sc, NR_syscalls)
> > > > +- && bitmap_empty(filter->sc_compat,
> > > > +- NR_compat_syscalls)) {
> > > > +- ret = -EEXIST;
> > > > +- goto error;
> > > > +- }
> > > > +
> > > > +- /* Disable all system calls */
> > > > +- bitmap_clear(filter->sc, 0, NR_syscalls);
> > > > +- bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls);
> > > > +- goto apply_filter;
> > > > +- }
> > > > +- syscall_nr = get_syscall_nr(name);
> > > > +- compat_syscall_nr = get_compat_syscall_nr(name);
> > > > +- if (syscall_nr < 0 && compat_syscall_nr < 0) {
> > > > +- ret = -ENOENT;
> > > > +- goto error;
> > > > +- }
> > > > +- if (syscall_nr >= 0) {
> > > > +- if (!test_bit(syscall_nr, filter->sc)) {
> > > > +- ret = -EEXIST;
> > > > +- goto error;
> > > > ++ switch (event->u.syscall.entryexit) {
> > > > ++ case LTTNG_SYSCALL_ENTRY:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ bitmap = filter->sc_entry;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ bitmap = filter->sc_compat_entry;
> > > > ++ break;
> > > > + }
> > > > +- bitmap_clear(filter->sc, syscall_nr, 1);
> > > > +- }
> > > > +- if (compat_syscall_nr >= 0) {
> > > > +- if (!test_bit(compat_syscall_nr, filter->sc_compat)) {
> > > > +- ret = -EEXIST;
> > > > +- goto error;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_EXIT:
> > > > ++ switch (event->u.syscall.abi) {
> > > > ++ case LTTNG_SYSCALL_ABI_NATIVE:
> > > > ++ bitmap = filter->sc_exit;
> > > > ++ break;
> > > > ++ case LTTNG_SYSCALL_ABI_COMPAT:
> > > > ++ bitmap = filter->sc_compat_exit;
> > > > ++ break;
> > > > + }
> > > > +- bitmap_clear(filter->sc_compat, compat_syscall_nr, 1);
> > > > ++ break;
> > > > ++ default:
> > > > ++ return -EINVAL;
> > > > + }
> > > > +-apply_filter:
> > > > +- if (!chan->sc_filter)
> > > > +- rcu_assign_pointer(chan->sc_filter, filter);
> > > > +- chan->syscall_all = 0;
> > > > +- return 0;
> > > > ++ if (!test_bit(syscall_nr, bitmap))
> > > > ++ return -EEXIST;
> > > > ++ bitmap_clear(bitmap, syscall_nr, 1);
> > > > +
> > > > +-error:
> > > > +- if (!chan->sc_filter)
> > > > +- kfree(filter);
> > > > +- return ret;
> > > > ++ return 0;
> > > > + }
> > > > +
> > > > + static
> > > > +@@ -1236,6 +1256,9 @@ const struct file_operations
> > > > lttng_syscall_list_fops = {
> > > > + .release = seq_release,
> > > > + };
> > > > +
> > > > ++/*
> > > > ++ * A syscall is enabled if it is traced for either entry or exit.
> > > > ++ */
> > > > + long lttng_channel_syscall_mask(struct lttng_channel *channel,
> > > > + struct lttng_kernel_syscall_mask __user *usyscall_mask)
> > > > + {
> > > > +@@ -1262,8 +1285,9 @@ long lttng_channel_syscall_mask(struct
> > > > lttng_channel *channel,
> > > > + char state;
> > > > +
> > > > + if (channel->sc_table) {
> > > > +- if (filter)
> > > > +- state = test_bit(bit, filter->sc);
> > > > ++ if (!READ_ONCE(channel->syscall_all) && filter)
> > > > ++ state = test_bit(bit, filter->sc_entry)
> > > > ++ || test_bit(bit,
> > > > filter->sc_exit);
> > > > + else
> > > > + state = 1;
> > > > + } else {
> > > > +@@ -1275,9 +1299,11 @@ long lttng_channel_syscall_mask(struct
> > > > lttng_channel *channel,
> > > > + char state;
> > > > +
> > > > + if (channel->compat_sc_table) {
> > > > +- if (filter)
> > > > ++ if (!READ_ONCE(channel->syscall_all) && filter)
> > > > + state = test_bit(bit -
> > > > ARRAY_SIZE(sc_table),
> > > > +- filter->sc_compat);
> > > > ++ filter->sc_compat_entry)
> > > > ++ || test_bit(bit -
> > > > ARRAY_SIZE(sc_table),
> > > > ++ filter->sc_compat_exit);
> > > > + else
> > > > + state = 1;
> > > > + } else {
> > > > +--
> > > > +2.19.1
> > > > +
> > > > diff --git a/meta/recipes-kernel/lttng/lttng-modules_2.12.2.bb
> > > > b/meta/recipes-kernel/lttng/lttng-modules_2.12.2.bb
> > > > index 0e1a209ce8..e36b327a08 100644
> > > > --- a/meta/recipes-kernel/lttng/lttng-modules_2.12.2.bb
> > > > +++ b/meta/recipes-kernel/lttng/lttng-modules_2.12.2.bb
> > > > @@ -11,6 +11,16 @@ include lttng-platforms.inc
> > > > SRC_URI = "https://lttng.org/files/${BPN}/${BPN}-${PV}.tar.bz2 \
> > > >
> > > > file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
> > > > file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
> > > > +
> > > > file://0001-Kconfig-fix-dependency-issue-when-building-in-tree-w.patch \
> > > > +
> > > > file://0002-fix-Move-mmutrace.h-into-the-mmu-sub-directory-v5.9.patch \
> > > > +
> > > > file://0003-fix-KVM-x86-mmu-Make-kvm_mmu_page-definition-and-acc.patch \
> > > > +
> > > > file://0004-fix-ext4-limit-the-length-of-per-inode-prealloc-list.patch \
> > > > +
> > > > file://0005-fix-ext4-indicate-via-a-block-bitmap-read-is-prefetc.patch \
> > > > +
> > > > file://0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch \
> > > > +
> > > > file://0007-fix-writeback-Drop-I_DIRTY_TIME_EXPIRE-v5.9.patch \
> > > > +
> > > > file://0008-fix-writeback-Fix-sync-livelock-due-to-b_dirty_time-.patch \
> > > > +
> > > > file://0009-fix-version-ranges-for-ext4_discard_preallocations-a.patch \
> > > > + file://0010-Fix-system-call-filter-table.patch \
> > > > "
> > > >
> > > > SRC_URI[sha256sum] =
> > > > "df50bc3bd58679705714f17721acf619a8b0cedc694f8a97052aa5099626feca"
> > > > @@ -36,7 +46,7 @@ SRC_URI_class-devupstream =
> > > > "git://git.lttng.org/lttng-modules;branch=stable-2.1
> > > >
> > > > file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
> > > > file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
> > > > "
> > > > -SRCREV_class-devupstream = "57ccbfa6a8a79c7b84394c2097efaf7935607aa5"
> > > > +SRCREV_class-devupstream = "ad594e3a953db1b0c3c059fde45b5a5494f6be78"
> > > > PV_class-devupstream = "2.12.2+git${SRCPV}"
> > > > S_class-devupstream = "${WORKDIR}/git"
> > > > SRCREV_FORMAT ?= "lttng_git"
> > > > --
> > > > 2.19.1
> > > >
> > > >
> >
> >
> >
> > --
> > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > thee at its end
> > - "Use the force Harry" - Gandalf, Star Trek II
--
- Thou shalt not follow the NULL pointer, for chaos and madness await
thee at its end
- "Use the force Harry" - Gandalf, Star Trek II
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